A conventional household oven allows a user to set a temperature for baking or cooking food. The oven heats an oven chamber to the desired temperature and attempts to maintain that temperature in the oven chamber for the duration of the cooking period. To heat the oven and maintain the oven temperature, the conventional household oven includes heating elements, a temperature sensor, and a controller. For the oven's basic operation, the heating elements are supplied with power to heat the oven chamber. The temperature sensor senses the temperature within the oven chamber and supplies a temperature measurement signal to the controller indicative of the temperature. Based on the temperature measurement signal, the controller compares the measured signal with the desired temperature/setpoint and sends a control signal to a heater drive. The heater drive is operatively connected to the heating elements, and is capable of varying the power to the heating elements to maintain the desired temperature setpoint within the oven chamber.
Typically temperature measurement using an RTD is done utilizing a regulated voltage supply along with amplifiers, and comparators that increase the gain of the voltage measured across the RTD. These measurements are usually performed using the low regulated power sources as the voltage supply. Regulation of the voltage as well as amplification of the circuit significantly increases the amount of materials required for the temperature measurement, the cost of the component, and the space required for the measurement device. Moreover, to compensate for inaccuracy based on the circuits' calibration values, the offset determined at calibration is typically added to the measured temperature value during operation, which is less accurate than desired.
The present invention is directed to overcoming or at least reducing the effects of one or more of the problems set forth above.